Cuprammonium yarn manufacture



being spun in funnels under normal spinning-conthe following table: 5

conditions; i. e., with hole diameters of 0.8 to 1.0 V 7 V mm., speedsof more than 25 meters per minute Hole di- Hardness 32: gg g gggggResulting and coagulating bath temperatures above 35 0., meter waterture per min. per min. mead 10 1 a product of inferior quality isobtained, and it is impossible to produce a continuous thread in this 00' cc, Meters manner. It has been ascertained that these .8 11 30 V p700 Breaks in r deficiencies are caused by too rapid a coagulation(Gil-man) 2 1329 35 2 of the spinning solution which is brought about VImssible- 15 by the salts contained in natural Well water. The m swig 30700 i 30 l lt t b ii strong coagulating efiect is mainly due'to calciuminsidfi carbonate present which forms the principal ing l n t l lt lggredient of the salts dissolved in such water, and, V g fggfi f thus, itbecomes practically impossible to obtain, 20 with well water of about 4German degrees of total hardness, under normal spinning conditions, Thlstable clearly shows that contmuous or calcium Sulfate, act to a lesserextent in an diameters of the spinning nozzles arereduced, and

the use of calcium bicarbonate containing water conditions which mayberemployed according to 30' exceed 0.6 mm. The temperatures of thecomventlon' 35 agulafiing bath may, as usual, be'kept within a Ewmplerange f from 30 0 'C- It iS'to be noted, Titer V 120 demers however,that lower temperatures, as low as 20 singlg filament; L3 deniers may bed. Since, especially, the calcium bi- 30 meters permmut 7 4:0 carbonateexerts Strong precipitating action, Water of hardwater V 55 havingdiameters smaller than 0.6 mm. and pref- 1. In the stretch-spinningprocess of producing 55 Patented 0a. 5, 1931. V r 2,095 220:

PATENT FFICE August Hartmann, Berlin-Liehterfelde, Germany, assignor toAmerican Bemberg Corporation, New York, N, Y., a corporation of Delawarer l 7 No Drawing. Application November 15, 19 33.56 1

rial No. 698,146., In Germany April 15, 1933 5 Claims. (Cl. 18-54)Untilthe present time, the principal require-1 erablywith openings ofabout 0.2 mm.in diameter. ment for the production ofcommercialartificial I The effect of the novel process which is charsilkfrom copper cellulose solutions, has been the acterized by the combineduse of hard Water and use of softened water, provided such solutions arerelatively narrow nozzle openings, is depicted in ditions. Experimentshave shown that by using hard instead of soft water under normalspinning Normal copper cellulose solution marketable products. The otherconstituents thlreads t be Produced by g i 3 of such hard water, forexample, calcium chloride ose solutlons Into hard Water prom e t e o eanalogous manner that threads extruded into hard water through 5 oneabject of my present invention is h use openings of normal size will notallow the manuof hard water containing especially calcium bimaturemarketabge productl f r carbonate. Ihave found by experimentation thatf0 Owmg are W0 examp es spmnmg the invention it being understood thatthese are 1s possible prov1ded the w1de openmgs of 0.8 mm. r r indiameter and above, heretofore employed, are gnfenpmy of lnustratlqnand} that replaced by nozzle openings the diameters of mt condltlons.qanbe vaned wlthout.

which have been considerably reduced, and do not partmg from the spmtand scope of the present the spinning conditions must be adjustedaccording tothe calcium bicarbonate content of the water. In order toobtain the best results, the following rule has been found and'must bestrictly adhered to: p I Example 2 V 45 The higher the bicarbonatecontent of water (hardness 11) Temperature of water 25C. Hole diameterof nozzles-" 0.15 millimeter present, 1. e., the so-called' transienthardness, Titer? denim Single filament 1.3 demers the smaller should bethe dlameter of the nozzle Speed 30 meters perminute openings. V I i rIn other words the hole diameter must be re- Water gz k zh 50 duced as adirect'function ofthe water hardness. Temperature of water"; C um VWhen'extremely hard water, for example, of more than 10 German degreesof hardness, is used,

Hole diameter of nozzles--- 0.2 millimeter it is advisable to operatewith nozzle openings I claim:

artificial silk, the step comprising extruding a cuprammonium cellulosesolution through a nozzle opening of about 0.15 to 0.6 millimeter indiameter into water, the said water having a hardness of more than 10German degrees and a temperature of about 20 to 35 C., the diameter ofthe nozzle opening being reduced within the range 0.15 to 0.6 millimeteras the hardness of the water increases.

2. In the stretch-spinning process of producing cuprammonium cellulosefilaments of about 1.3 deniers, the step comprising extruding acuprammonium cellulose solution at a speed of about 30 meters per minutethrough a nozzle opening of about 0.15 millimeter in diameter intoWater, said water having a hardness of about 11 German degrees and atemperature of about 25 C. 1

3. In the stretch-spinning proces of producing cuprammonium cellulosefilaments, the step comprising extruding a cuprammonium cellulosesolution ata speed of about 30 meters per minute through a nozzleopening of about 0.2 millimeters in diameter into Water, said waterhaving a hardness of about 11 German degrees and a temperature of about30 C.

4. In the stretch-spinning process of producing artificial silk, thestep comprising extruding a cuprammonium solution through a nozzlehaving openings of a diameter of about 0.15 to 0.6 millimeter into veryhard water, the said Water having a hardnes of above 10 German degrees,the diameter of the said nozzle opening varying within the range of 0.15to 0.6 in inverse ratio to the increasing hardness of the Water above 10German degrees.

5. In the stretch-spinning process of producing artificial silk byforcing a cuprammonium cellulose solution through suitable openings intohard Water having a hardness of over 4 German degrees, the methodcomprising determining the hardness of the said Water and selectingdiameters of 0.6 millimeter to 0.15 millimeter as an 20 inverse functionof the hardness of the water.

AUGUST HARTMANN.

